Plug-in solar panels: what matters and what doesn’t
Three things decide how good a plug-in solar panel is for you: how many watts it makes, how much space it takes, and whether it matches your inverter. Brand matters less than where you put it.
Updated October 2026
Watts and efficiency
The watt rating is what the panel makes in perfect lab conditions. Real-world output is lower, especially when the panel hangs straight up. Efficiency tells you how much power you get per square foot. Higher efficiency matters when space is tight.
Rigid, flexible or bifacial
| Type | Good | Watch out |
|---|---|---|
| Rigid glass | Most power per dollar, lasts longest | Heavy, needs a solid mount |
| Flexible | Light, fits odd spaces | Less power, ages faster |
| Bifacial | Extra power from the back side | Little gain against a wall or balcony |
Panels and inverters belong together
A plug-in kit is tested as a set. The certification most state laws require, UL 3700, covers the equipment as it’s sold. Swapping in a different panel can push the inverter outside its range, or take the system outside what was certified. Buy panels and inverter together, from the kit maker. More on UL 3700.
The spot beats the panel
The same panel can make three times as much on a sunny south-facing stand as on a north-facing railing. Sort out the location first. Direction guide.
Common questions
How many watts do I need?
For most homes, about 800 W of panels covers the power that's always running during the day. More mainly adds midday power you can't use. Which size to pick.
Do panels work in partial shade?
Poorly. A shadow across part of a panel can cut its output by much more than the shaded area suggests. Pick the spot with the fewest shadows during the middle of the day.
Can I use any solar panel with a plug-in kit?
Only one the microinverter is made for. The panel's voltage and current have to match the inverter's input range. Mixing parts can also break the certification that your state's law may require.
Monocrystalline or polycrystalline?
Almost every panel sold today is monocrystalline. It makes more power from the same space, which is exactly what you want on a balcony.